one of the things that we need to figure out for long distance/duration space flight is the effect 0g has on bone density. long duration 0g causes significant bone density loss as well as increasing height a couple inches due to the expansion of your spine and other hilarious effects on the human body. well there is now evidence that just taking osteoporosis drugs can prevent a significant amount of loss. in weightlessness, an astronaut who exercises regularly still loses 5-7% of their bone density in 6 months. recent tests on the ISS has shown that taking the drugs can reduce the bone density loss to almost nothing. that is quite a finding! our thanks should go to the first test subject who volunteered. this astronaut was the japanese astronaut Wakata. thank you wakata-san!read here for more details: http://www.yomiuri.co.jp/dy/national/T111205005649.htm (blurb)more info: http://www.jaxa.jp/article/special/expedition/matsumoto01_e.html